Laboratory balances, particularly microbalances, are extremely reactive to air movements, dust and also static charges. It is known to protect such balances with various types of shields and although the shields available are effective against air movement and dust, they are of little or no value when static charges develop on or around the balance or on the shield itself and such static charges cause considerable difficulty in obtaining accurate and reproducible weighings.
It is also known to dissipate static charges by using a small amount of radioactive material placed near the balance pan, but such a technique is frequently not an acceptable solution to the problem because of environmental hazards.
Another known technique for neutralizing static effects is the use of hydroscopic sprays or wipes, but such treatments have only temporary effects since they rapidly dissipate.
Metal shields have also been used to overcome static effects, but such shields are opaque and do not lend themselves to use with a balance where the operator needs to see the balance pan and its contents.